System and method for dynamic switching between batteries in a dual battery system

Abstract

A system and method for dynamically switching power supply in a dual battery system to minimize unbalanced wear levels in the primary and secondary batteries. If the operating temperature of the primary battery reaches a reliability temperature threshold but the operating temperature of the secondary battery is less than the reliability temperature threshold, the controller switches a primary battery indicator to designate the secondary battery as the primary battery. If the operating temperature of the primary battery reaches a pre-shutdown temperature but the operating temperature of the secondary battery is less than the pre-shutdown temperature, the controller switches a primary battery indicator to designate the secondary battery as the primary battery. If a difference between the wear levels of the batteries exceeds a wear level difference threshold, the controller switches a primary battery indicator to designate the secondary battery as the primary battery.

What is claimed is: 
     
       1. A battery system for an information handling system, the battery system comprising:
 a first battery; 
 a second battery; 
 a controller; and 
 a memory medium communicatively coupled to the controller, the memory medium storing a primary battery indicator designating the first battery as the primary battery and a set of instructions executable by the controller to:
 determine an operating temperature of the first battery; 
 if the operating temperature of the first battery is equal to or greater than a reliability temperature threshold:
 determine an operating temperature of the second battery; and 
 
 if the operating temperature of the second battery is less than the reliability temperature threshold, switch the primary battery indicator in the memory medium to designate the second battery as the primary battery; and 
 if the operating temperature of the first battery and the operating temperature of the second battery are equal to or greater than the reliability temperature threshold, the set of instructions are further executable by the controller to:
 determine if the operating temperature of the first battery is equal to or greater than a pre-shutdown temperature; and 
 if the operating temperature of the first battery is equal to or greater than the pre-shutdown temperature and the operating temperature of the second battery is less than the pre-shutdown temperature:
 switch the primary battery indicator in the memory medium to designate the second battery as the primary battery. 
 
 
 
 
     
     
       2. The battery system of  claim 1 , wherein:
 the first battery comprises a first battery management unit (BMU); 
 the second battery comprises a second BMU; and 
 the set of instructions are executable by the controller to:
 communicate with the first BMU to determine a wear level of the first battery; 
 communicate with the second BMU to determine a wear level of the second battery; 
 determine a difference between the wear level of the first battery and the wear level of the second battery; and 
 switch the primary battery indicator to designate the second battery as the primary battery if the difference between the wear level of the first battery and the wear level of the second battery is equal to or greater than a wear level difference threshold. 
 
 
     
     
       3. The battery system of  claim 2 , wherein the wear level difference comprises a ratio of the wear level of the first battery and the wear level of the second battery. 
     
     
       4. The battery system of  claim 2 , wherein:
 the wear level of the first battery corresponds to a number of charging/discharging cycles of the first battery; 
 the wear level of the second battery corresponds to a number of charging/discharging cycles of the second battery; and 
 the wear level difference comprises a difference between the number of charging/discharging cycles of the first battery and the number of charging/discharging cycles of the second battery. 
 
     
     
       5. The battery system of  claim 1 , wherein
 the wear level of the primary battery and the wear level of the secondary battery are associated with time operated above the pre-shutdown temperature. 
 
     
     
       6. A dual battery system for an information handling system, the dual battery system comprising:
 a first battery having a first battery management unit (BMU); 
 a second battery having a second BMU; 
 a controller communicatively coupled to the first BMU and the second BMU; and 
 a memory medium communicatively coupled to the controller, the memory medium storing a primary battery indicator designating the first battery as a primary battery and a set of instructions executable by the controller to:
 determine an operating temperature of the first battery; 
 if the operating temperature of the first battery is equal to or greater than the reliability temperature threshold, determine an operating temperature of the second battery; and 
 if the operating temperature of the second battery is less than the reliability temperature threshold, switch the primary battery indicator in the memory medium to designate the second battery as the primary battery; 
 if the operating temperature of the first battery and the operating temperature of the second battery are equal to or greater than the reliability temperature threshold:
 determine if the operating temperature of the first battery is equal to or greater than a pre-shutdown temperature; and 
 if the operating temperature of the first battery is equal to or greater than the pre-shutdown temperature and the operating temperature of the second battery is less than the pre-shutdown temperature: 
 switch the primary battery indicator in the memory medium to designate the second battery as the primary battery; 
 
 
 wherein the set of instructions are further executable by the controller to:
 read a wear level of the first battery; 
 read a wear level of the second battery; 
 determine a difference between the wear level of the first battery and the wear level of the second battery; and 
 if the difference between the wear level of the first battery and the wear level of the second battery is equal to or greater than the wear level difference threshold, switch the primary battery indicator to designate the second battery as the primary battery. 
 
 
     
     
       7. The dual battery system of  claim 6 , wherein:
 the wear level of the first battery comprises a percentage of a charge capacity of the first battery; 
 the wear level of the second battery comprises a percentage of a charge capacity of the second battery. 
 
     
     
       8. The dual battery system of  claim 6 , wherein:
 the wear level of the first battery corresponds to a number of charging/discharging cycles of the first battery; 
 the wear level of the second battery corresponds to a number of charging/discharging cycles of the second battery; and 
 the wear level difference comprises a difference between the number of charging/discharging cycles of the first battery and the number of charging/discharging cycles of the second battery. 
 
     
     
       9. The dual battery system of  claim 6 , wherein the wear level difference comprises a ratio of the wear level of the first battery and the wear level of the second battery. 
     
     
       10. A portable information handling system contained in a chassis, the portable information handling system being capable of drawing power from a dual battery system comprising:
 a first battery having a first battery management unit (BMU); 
 a second battery having a second BMU; 
 a controller communicatively coupled to the first BMU and the second BMU; and 
 a memory medium communicatively coupled to the controller, the memory medium storing a primary battery indicator designating the first battery as a primary battery and 
 set of instructions executable by the controller to:
 determine an operating temperature of the primary battery; 
 if the operating temperature of the primary battery is equal to or greater than the reliability temperature threshold:
 determine an operating temperature of the secondary battery; and 
 
 if the operating temperature of the secondary battery is less than the reliability temperature threshold, switch the primary battery indicator to designate the secondary battery as the primary battery; 
 if the operating temperature of the primary battery and the operating temperature of the secondary battery are equal to or greater than the reliability temperature threshold, the set of instructions are further executable by the controller to:
 determine if the operating temperature of the primary battery is equal to or greater than a pre-shutdown temperature; 
 if the operating temperature of the primary battery is equal to or greater than the pre-shutdown temperature, determine if the operating temperature of the secondary battery is equal to or greater than the pre-shutdown temperature; 
 if the operating temperature of the secondary battery is less than the pre-shutdown temperature, switch the primary battery indicator in the memory medium to designate the secondary battery as the primary battery; and 
 if the operating temperature of the primary battery and the operating temperature of the secondary battery are equal to or greater than the pre-shutdown temperature, send a signal to power down the information handling system; and 
 
 
 wherein the set of instructions are further executable by the controller to:
 read a wear level of the first battery; 
 read a wear level of the second battery; 
 determine a difference between the wear level of the first battery and the wear level of the second battery; and 
 if the difference between the wear level of the first battery and the wear level of the second battery is equal to or greater than a wear level difference threshold, switch the primary battery indicator in the memory medium to designate the second battery as the primary battery. 
 
 
     
     
       11. The portable information handling system of  claim 10 , wherein:
 the wear level of the first battery comprises a percentage of a charge capacity of the first battery; and 
 the wear level of the second battery comprises a percentage of a charge capacity of the second battery. 
 
     
     
       12. The portable information handling system of  claim 11 , wherein:
 the wear level of the first battery corresponds to a number of charging/discharging cycles of the first battery; 
 the wear level of the second battery corresponds to a number of charging/discharging cycles of the second battery; and 
 the wear level difference comprises a difference between the number of charging/discharging cycles of the first battery and the number of charging/discharging cycles of the second battery. 
 
     
     
       13. The portable information handling system of  claim 10 , wherein the wear level difference threshold comprises a ratio of the wear level of the primary battery and the wear level of the secondary battery. 
     
     
       14. The portable information handling system of  claim 10 , wherein the wear level of the primary battery and the wear level of the secondary battery are associated with time operated above the pre-shutdown temperature.